Tape clamp



May 5, 1959 l J. P. ELLswoRTH 2,884,673

TAPE CLAMP Filed Jan. 14, 1958 Err@ United tates Patent TAPE CLAMP Joseph P. Ellsworth, Dubuque, Iowa Application January 14, 1958, Serial No. 708,938

3 Claims. (Cl. 24-126) This invention relates to a clamp, and more particularly to a clamping device that is adapted to be attached to and detached from flexible tapes, cable, wire or the like to facilitate the pulling of electrical wires and the like through conduits and to facilitate other operations that would otherwise be exceedingly diicult.

In the wiring of houses and commercial buildings, it frequently becomes necessary by means of a exible tape or cable to pull the actual wiring through a conduit. This operation is often made difficult or complicated, due to the location of the various junction boxes or panels at remote and otherwise inaccessible locations in the building. In many instances, the remote, inaccessible location of a particular junction box makes the wire installation or rewiring operation extremely tedious and time consuming, due to the difficulty encountered in setting up the necessary rigging and equipment to perform the pulling operation.

In addition, the possibility of bending or breaking the wire when attempting to pull the same through a conduit located in an awkward or inaccessible junction box is substantially enhanced, with the attendant added expense and loss of time. The present invention offers a solution to these problems in the form of an improved tape clamping device, that is adapted to be readily attached to a conventional steel tape or cable for facilitating installation or removal of electrical wires in or from a length of conduit between junction boxes, however, remote or inaccessible their locations.

In addition to being easily connected to the tape, such that the clamp may be readily pulled with a set of blocks or by hand, the clamp of the present invention may also be effectively used as a ram for forcing a tape or cable through tortuous or otherwise diicult runs.

Briefly described, the present invention contemplates an elongated clamp body having a groove formed lengthwise thereof to permit the clamp body to receive the tape at any point along its length. The clamp body is formed with a cam surface, adjacent one end of the tape-receiving groove or slot, and includes a relieved portion, adjacent the other end of the slot.

The clamp body carries a slidable wedge-shaped block therein having a cam surface formed thereon, complemental to the cam surface in the clamp body. A threaded member, such as an eyebolt, is freely received in a bore in the clamp body and is threadedly engaged with the slidable block member so that rotation of the threaded member will cause the slidable block to move toward or away from the cam surface in thev clamp body.

A movable jaw member having complementally formed cam surfaces with respect to the cam surfaces on the clamp body and slidable block is disposed between the respective cam surfaces forementioned, and is operable in response to rotation of the threaded member and resulting reciprocal movement of the slidable block to clamp a tape or other exible material in the clamp body.

The jaw portion of the clamp device is formed with a trapezoidally wedge-shaped body portion and an oiset portion, such that when the jaw member is brought into clamping engagement with a tape positioned in the slot of the clamp body, the lexible material will be clamped in an offset position, due to the offset portion of the jaw member and relieved portion in the clamp body. The offset clamped arrangement of the tape in the clamp device assures a stronger connection of the device to the tape, such that extremely large pulling forces may be applied to the device without danger of slippage.

The clamping device of my invention may be readily attached to or released from the ytape or other flexible material 'by a simple manipulation of the threaded member to unlock the slidable block in the clamp body and permit the jaw member to release the tape. The threaded member also forms a convenient attachment point for cables or rope, such as are used to apply a pulling force to the tape, and to this end may take the form of a threaded eyebolt, though any other construction could be utilized instead.

Accordingly, it is an object of the present invention to provide an improved clamping device.

Another object of the present invention is to provide an improved clamping device that is adapted to be readily attached to or removed from tapes, or the like, used to install electrical wiring.

Still another object of `the present invention is to p-rovide an improved tape clamping device that will substantially reduce the diiculty experienced by an operator in pulling a wire through a junction box in a remote or inacessible location, or through a conduit that is tortuous or for other reasons renders pulling of the wire therethrough diicult.

A further object of the present invention is to provide an improved tape clamping device that may be effectively used for forcing a tape through a conduit either by pulling or as a ram.

Another object of the present invention is to provide an improved tape clamping device in which the means for locking the device to the tape forms a convenient attachment point for pulling the device and attached tape either by hand or through a system of blocks.

Still another object of the present invention is to provide an improved tape clamping device that is positive in action, simple to construct and manufacture, easy to service and maintain, and economical.

Many other objects and advantages of the present invention will be come manifest to those versed in the art upon making reference to the detailed description and accompanying sheet of drawings that follow, in which like reference numerals and letters have been used to identify identical parts, and which form a part of this specification.

In the drawings:

Figure l is a bottom plan view of my invention, showing the general arrangement and position of the device when attached to a tape;

Figure 2 is a cross-sectional view, taken substantially above the line II-II of Fig. 1, with parts in elevation, showing the general position and arrangement of the parts before the device has been clamped to the tape;

Figure 3 is a View similar to Figure 2, but showing the position of the parts when the device has been clamped to the tape prior to a pulling operation; and

Figure 4 is an end elevational view.

As shown on the drawings:

As shown in Figures l, 2 and 4, the tape clamp assembly of the invention is designated generally by the reference numeral 10 and includes an elongated clamp body B, of a somewhat oval cross-section, a slidable 3 block member K carried by the clamp body member B, a threaded member S that engages the slidable block member K, and a jaw member J, that is disposed in the body member in the clamp body B and retained therein by the slidable block member K.

A conventional electricians steel tape T is illustrated in conjunction with each of the figures, but it should be understood that any other suitable exible material such as cable, wire or the like, could be used in place of 4the tape T in conjunction with the clamp assembly 10.

The clamp body B may be constructed of any suitable material having the desired strength characteristics, as for example steel or plastic, and is formed with a generally yoval exterior 11 having a narrow rounded upper portion 11a and a wider lower portion 11b. The clamp body also includes end face portions 12 and 13, respectively.

The clamp body B is additionally formed with a longitudinally extending slot or groove 14 (Figures 2 and 4), and a generally hollow interior 16, which receives theslidable block member K, jaw member I and a portion of the threaded member S therein, as will be described in more detail later.

As best shown in Figures 2 and 4, the groove or slot 14 extends axially of the clamp body B and is outwardly recessed as at 17 to provide a stepped configuration to the groove 14 for a substantial portion of its length, for a function to be described in more detail later.

The hollow interior 16 of the clamp body B forms a generally rectangular shaped chamber or slot portion 18, which forms a guide path for #the slidable block member K and jaw member I. The hollow interior 16 of the clamp body B also is formed with an inclined cam surface 19, which registers with the axial extending groove or slot 14, and is in opposed relationship to the shoulder defined bythe outwardly recessed portion 17 of the groove or slot 14.

The angle, length and surface hardness of the cam surface 19 may be varied in accordance with the operating conditions contemplated, and where a greatly extended useful life is desired, a hardened insert (not shown) may be employed to resist wear and lessen friction with the mating surface of the jaw member I.

It will also be understood that a multiple cam surface construction could be employed in place of the cam surface 19 in the clamp body B in order to obtain the desired clamping result in a particular installation.

The slidable block member K may have any desired shape, such as will enable it to be guidably reciprocated in the rectangular slot portion 18 of the clamp body B, and to this end is preferably of a generally rectangular shape, having a vertical height sufcient to permit sliding movement along the bot-tom of the slotted chamber 1S, and such that its upper surface is substantially parallel to the bottom of the ygroove or slot 14. The slidable block member K also includes a cam surface 20 that is complemental in extent and position to the cam surface 19, for a coacticn therewith and with the jaw member J. The cooperative action of the earnl surface 20 with the cam surface 19 serves `to cause the jaw member J to clamp the tape T as the block K is moved into the position shown in Fig. 3. The slidable block K, to effect such movement, includes a threaded bore 21 therethrough for receiving the threaded portion of the threaded member S to thus provide for controlled reciprocal movement of said block as the member S is rotated.

The slidable block member K may be formed of any suitable material having the desired strength and work characteristics, similar to the material used in the construction of the clamp body B and if desired, may be provided with a hardened insert (not shown) to provide a wear resistant cam surface 20.

Thus it will be appreciated that the opposed cam surfaces 19 and 20 of the clamp body B and the block K make possible a vise-like action that is controlled by manipulation of the threaded member S, the cam surfaces 19 and 20 being effective to exert an outward movement of the wedge-shaped jaw member I, to clamp a tape T, or other flexible material, between the jaw member J and the inwardly facing surfaces of the groove 14.

The jaw member I includes a generally trapezoidally shaped body portion 22 having an upper surface 22a and a lower surface 22h, and a rectangularly shaped outwardly offset foot portion 23, also having an upper surface 23a and a lower surface 2317, and which is positioned in the hollow interior 16 of the clamp body B adjacent the outwardly recessed portion 17 for coaction therewith.

The trapezoidally shaped body portion 22 of the jaw member J includes a cam surface 24 for coaction with the cam surface 19 of the clamp body B, and a cam surface 26 for coaction with the cam surface 20 of the slidable block member K.

The upper surface 23a of the depending foot portion 23 extends somewhat above the upper surface 22a of the body portion 22 to define a shoulder 27 therebetween, which serves as a guide to direct the tap T through the slot 14 when the tape clamp assembly 10 is slipped endwise over a tape.

The lower surface 23b intersects the cam surface 26 at a point 28 somewhat below the plane of the upper surface 22a of the jaw member body 22 and thus serves to maintain the lower surface 22b of the jaw member body in spaced relation to the threaded member S.

As most clearly shown in Figure 3, the upper surface 23a is elevated above the upper surface 22a of the jaw member I by an amount substantially equal kto the depth of the recessed portion 17 of the slot 14, less an amount substantially equal to the thickness of a conventional tape, such that when the jaw member J has moved upwardly into the slot 14 to clamp the tape T, the tape will assume an angular configuration, to further assist the clamping action and thus prevent any slippage of the clamp assembly 10 on the `tape T when a separating force is applied thereto.

The jaw member I is formed with a generally rectangular cross-section to permit its free movement within the hollov interior 16 of the clamp body B under the wedging action exerted by the coacting cam surfaces.

The jaw member J is formed from a material having yhigh strength and wear characteristics, such as `hardened steel or the like, to provide a long and useful life without excessive wear to the various cam surfaces.

The threaded member S has been illustrated in the form of an eyebolt, having a threaded screw portion 29 and an eye portion 30, which facilitates manipulation of the screw portion to move the slidable block member K in the clamp body B. The eye portion 30 provides a convenient point of attachment for a rope or cable.

It will be understood that any other convenient threaded member could be substituted for the threaded member S in order to' provide a means for advancing the slidable block member K, and that a non-integral attachment point could also be provided for applying force to the tape clamp assembly 10, other than the eye 30. In order to provide a bearing surface for the screw member S against the clamp body B, the eye portion 30 thereof is desirably enlarged as at 31, relative to the threaded screw portion 29, to form an annular shoulder 32.

As shown in Figure 4, the slot 14 is recessed as at 33 centrally of the clamp body B, to define a retaining shoulder 34 which serves to retain the tape T in the clamp body B and prevent unintended lateral displacement thereof while the threaded member S is advancing the jaw member J into clamping engagement with the tape T.

It should be understood that the -complementally engaging surfaces in the slot 14, recess portion 17, and the upper surfaces 22a and 23a of the jaw member I could be modified or recessed to a hemispherical configuration when the clamp assembly 10 is to be used primarily with cables or wires having a generally circular cross-section.

It should also be understood that various sized jaw members J could be interchangeably used to accommoldate various sizes of tapes, cables or wires, and the size of the tape clamp assembly varied proportionately.

Referring to Figures 2 and 3, the operation of the tape clamp assembly 10 will now be described.

With the jaw member I `and slidable block member K in the position illustrated in Figure 2, the clamp assembly 10 is applied to the tape T in such manner that the tape T passes through the slot 14 and into the recessed portion 33 of the slot 14, for retention therein against the shoulder 34. Due to the greater mass of the enlarged lower portion 11b of the clamp body B, the clamp assembly 10 will tend to assume the vertical orientation illustratefd in Figures 2-4. Tightening of the threaded member S advances the block K toward the cam surface 19 initially bringing into engagement the cam surfaces 20 and Z6 and 19 and 24 to thus start the jaw member J moving upwardly. Continued threaded engagement of the threaded member S in the slidable block member K raises the jaw member I in the slot 14 to the full locked position illustrated in Figure 3.

Due to the offset arrangement between the upper surfaces 22a and 23a of the jaw member J and the recessed portion 17 of the slot 14, a tape T assumes an angular offset, illustrated in Figure 3, that provides an additional clamping or locking action toward the tape in the clamp assembly 10.

With the components of a tape clamp assembly 10 in the position illustrated in Figure 3, the device is suited for the application of a force thereto to pull the tape T. While the clamp assembly 10 is best suited for a pulling operation, it can very effectively be used as a ram to force a tape through a tortuous conduit as well.

The clamp assembly 10 is readily released from its locked position on the tape by a reverse rotation of the threaded member S, to permit the clamp assembly to be removed or moved to a new point along the tape T for an additional pull.

While only one embodiment of the invention has been herein illustrated and described, it should be understood that various modifications and variations may be effected without departing from the scope of the novel concepts herein disclosed.

This application is a continuation-in-part application of my application Serial No. 678,735, led August 16, 1957.

I claim as my invention:

1. A clamping device adapted to engage a flexible tape or the like to facilitate the application thereto of a longitudinal force, comprising an elongated clamp body having a slot formed therethrough to permit said clamp device to be slipped over said tape, said clamp body also having a stationary :cam surface formed therein adjacent one end of said slot, a slidable member in said clamp body having a cam surface formed thereon for coaction with said stationary cam surface, a threaded member rotatably but longitudinally stationarily mounted within said body and threadedly connected to said sl-idable member to move the same relative to said stationary cam surface, and a jaw member disposed between the cam surfaces of said clamp body and of said slidable member and having complemental cam surfaces formed thereon for coaction therewith to wedgingly force said jaw member into clamping engagement with said tape in response to proper rotation of said threaded member.

2. A clamping device adapted to engage a flexible tape or the like to facilitate the application thereto of a longitudinal force, comprising an elongated clamp body having a longitudinally extending slot formed therein to permit said device to be slipped over said tape at any point along its length, said clamp body having a stationary cam surface adjacent one end of said slot and a relieved portion formed therein toward the other end of said slot, a slidable block member in said clamp body having an opposed cam surface movable for coaction with said stationary cam surface, a threaded member rotatably mounted for non-linear movement within said clamp body and threadedly connected to said slidable block member to effect reciprocable movement thereof relative to said stationary cam surface, and a jaw member having a camsurfaced body portion ldisposed between said opposed cam surfaces for wedge-like coaction therewith and an oset portion extending in opposed relation to said relieved portion, said threaded member being rotatable to move the body portion and offset portion of said jaw member into clamping engagement with said tape with said offset portion cooperating with said relieved portion of saild clamp body.

3. A clamping device adapted to engage a flexible tape or the like to facilitate the application thereto of longitudinal force, comprising an elongated clamp body having slot formed therethrough to permit said device to be slipped over said tape at any point along its length, said clamp body having a stationary cam surface and a relieved portion formed in said slot, a slidable block member having a cam surface formed thereon and movable for coaction with said stationary cam surface, a threaded member carried by said clamp body for rotation without linear movement and threadedly connected to said slidable block member to provide reciprocable movement thereof toward said stationary cam surface, and a jaw member having a cam-surfaced body portion disposed between said stationary and movable cam surfaces andI an olset portion for cooperation with said relieved portion, said threaded member being operable to move the body portion and offset portion of said jaw member into clamping engagement with said tape with said olfset portion cooperating with said relieved portion.

References Cited in the file of this patent UNITED STATES PATENTS 746,086 Hoyt et al. Dec. 8, 1903 1,948,061 Bowen Feb. 20, 1934 

